Gurren Laggan is the best mecha, the reason being as long as you have will power it can regenerate and and it can be rebuilt through spiral power, aside from that the ability to warp through time. Its almost like a green lantern thing but mecha thus why some gurren laggan art work has cross over colors of green lantern

I have to rep The Big O here...Its just so perfect in every way. While Gurren Lagann was one of the most fun anime I have ever seen, I have never been mindfucked as hard as when I watched The Big O and I loved every second of it

The best Mecha anime has the best innuendo, that said, AQUARION! Seriously though, Gurren Lagann started strong but lost so much steam I could barely finish it. I like Gundam, Evangelion, and even Valvrave more...and Macross has nostalgia going for it.